1. Field of the Invention
The invention relates to a control unit for controlling an a-c control element having full-wave control and, in particular, to a control unit of a type comprising a pulse generator which is synchronized to a line voltage and which generates firing pulses that can be applied to the firing electrodes of the thyristors of an a-c control element via a pulse transformer.
2. Description of the Prior Art
Control units of the above type and a-c control elements controlled thereby are known in the art and are commercially available. Such units and control elements are predominantly used for purposes of temperature control, and can be used to regulate temperature in conjunction with a continuous or bang-bang (on-off) control. Via these prior art control units, a pulse of approximately 180.degree. is applied to the firing electrodes of the thyristors of the a-c control element for each gated halfwave of the a-c supply voltage. These pulses necessitate the use of large transformers which make the arrangements relatively expensive.
It is therefore an object of the present invention to provide a control unit of the above type which is designed so as to eliminate the need for large transformers.